From 019c0f40e9668703986d638f8e6d415d6224ab4a Mon Sep 17 00:00:00 2001
From: Igor Pecovnik <igor@armbian.com>
Date: Mon, 18 May 2026 05:47:27 +0200
Subject: [PATCH] artifact-rootfs: surface git-log failure when computing
 configng hash

Original code masked git failures with `|| echo "unknown"` - the
build silently fell through to a degraded cache key without telling
the operator anything. A torn cache/sources/armbian-configng clone,
broken HEAD, or permissions glitch was indistinguishable from a
healthy "couldn't compute" state.

Capture stdout+stderr from git log, branch on exit status, and
display_alert the git error text when rc != 0. Still falls through
to "unknown" so the build completes - this is a best-effort
caching knob, not a build-blocker, and the downstream check in
create-cache.sh already skips the fingerprint fold on "unknown".

Scope kept exactly as before: BUILD_DESKTOP=yes only, path-filtered
to tools/modules/desktops/. CLI builds don't invoke armbian-config
at build time and configng content outside the desktop subtree
doesn't reach the rootfs from a build-time path, so broadening the
filter would only churn cache for no benefit. Comment touch-up in
create-cache.sh documents that scoping for future readers.
---
 lib/functions/artifacts/artifact-rootfs.sh | 25 ++++++++++++++++++++--
 lib/functions/rootfs/create-cache.sh       |  4 +++-
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/lib/functions/artifacts/artifact-rootfs.sh b/lib/functions/artifacts/artifact-rootfs.sh
index 0a1bc6c73e0f..ffd2405e482e 100644
--- a/lib/functions/artifacts/artifact-rootfs.sh
+++ b/lib/functions/artifacts/artifact-rootfs.sh
@@ -18,12 +18,33 @@ function artifact_rootfs_config_dump() {
 	# Track the latest commit touching configng's desktop definitions.
 	# Any change to YAML, parser, or module code in tools/modules/desktops/
 	# invalidates the desktop rootfs cache — the package list, browser
-	# mapping, tier overrides, or branding may have changed.
+	# mapping, tier overrides, or branding may have changed. Scoped to
+	# desktop builds and the desktop subtree because armbian-config is
+	# only invoked at build time for desktop installs
+	# (`module_desktops install mode=build`); for CLI builds the .deb
+	# is just installed and its contents don't affect the rootfs.
 	if [[ "${BUILD_DESKTOP}" == "yes" ]]; then
 		declare configng_desktops_hash="undetermined"
 		local configng_dir="${SRC}/cache/sources/armbian-configng"
 		if [[ -d "${configng_dir}/.git" ]]; then
-			configng_desktops_hash="$(git -C "${configng_dir}" log -1 --format=%H -- tools/modules/desktops/ 2>/dev/null || echo "unknown")"
+			# Capture stdout + stderr, then branch on exit status. This is
+			# a best-effort knob for cache-invalidation, not a build
+			# blocker - if git can't read this clone (torn checkout,
+			# stale files, broken HEAD, permissions), we warn and fall
+			# through to "unknown" rather than aborting an hour-long
+			# build. The downstream check in create-cache.sh skips the
+			# fingerprint fold on "unknown" / "undetermined" — the
+			# build still produces a valid image, it just doesn't get
+			# the configng-aware cache bust.
+			declare git_out git_rc
+			git_out="$(git -C "${configng_dir}" log -1 --format=%H -- tools/modules/desktops/ 2>&1)"
+			git_rc=$?
+			if (( git_rc == 0 )); then
+				configng_desktops_hash="${git_out}"
+			else
+				display_alert "configng_desktops hash: git log failed (rc=${git_rc}) in ${configng_dir}" "${git_out}" "warn"
+				configng_desktops_hash="unknown"
+			fi
 		fi
 		artifact_input_variables[CONFIGNG_DESKTOPS_HASH]="${configng_desktops_hash}"
 	fi
diff --git a/lib/functions/rootfs/create-cache.sh b/lib/functions/rootfs/create-cache.sh
index eafd7aed5eb5..2c9f4905c1a5 100644
--- a/lib/functions/rootfs/create-cache.sh
+++ b/lib/functions/rootfs/create-cache.sh
@@ -57,7 +57,9 @@ function calculate_rootfs_cache_id() {
 	# this, a configng commit that changes which packages a DE
 	# installs leaves the existing rootfs tarball untouched in the
 	# cache and every subsequent build cache-hits the pre-change
-	# version.
+	# version. Scoped to desktop builds: CLI images don't invoke
+	# armbian-config at build time, so configng content doesn't
+	# affect their rootfs.
 	#
 	# CONFIGNG_DESKTOPS_HASH is set by artifact_rootfs_config_dump
 	# above from `git log -1 -- tools/modules/desktops/` in the